American Revolution - Yep
War of 1812 - No - Despite conscription of American sailors into the Royal Navy and blocking trade with France, invading Canada wasn't the answer. America didn't benefit from this war, with everything being returned to the way it was and nothing done to resolve the causes for war.
Texan War of Independence - No - Settlers decide they like Texas, so decide to take it from Mexico
Mexican-American War - No - Mexico really shouldn't have bothered, as the Texas annexation was voluntary
Crimean War - No - European powers bicker over who is the "protector of the Holy Land".
Spanish-American War - No - US decides they want to protect their interests in Cuba, rant about atrocities there, then finally find an excuse with the sinking of a ship they just assume the Spanish are responsible for
Philippine-American War - No - US enforces their will on the Filipinos and takes their country as a colony (without calling it that)
World War 1 - No - European powers go to war over military rivalries. American entry is justified.
World War 2 - Yes - France and Britain were right to declare war on Germany
Malayan Insurgency - Yes - Minority Communist insurgents try to take country by force even though the British were planning on giving Malaya independence
Korean War - Yes - Almost complete support from the UN is obtained. However, it wasn't about Democracy - South Korea was a poor little country run by an absolute crackpot dictator
French wars in Indochina and Algeria - No - France tries to hang onto colonies that want independence in a time when everyone else was conceding theirs
Vietnam War - No - South Vietnam is an disunified, corrupt country with a new government coming in frequently. America makes up attacks on their Navy as an excuse to get militarily involved.
Grenada - Yes - They should have asked the British first, though
Panama - No - Causes remain dubious to this day, and wouldn't justify a modern war.
Desert Storm - Yes - It was about oil then, but what the hey! Iraq shouldn't have tried to settle their war debts by invading Kuwait.
Kosovo War - Yes
Afghanistan - Yes - This time, it's obvious who to target. Everyone contributes alongside the American effort.
Iraq War - No - The most frequently cited causes were of dubious nature, then are proved to be false after the invasion. Meanwhile, Coalition makes no effort to liberate the other oppressed peoples of the world.